<script type="text/javascript" src="jquery.js"></script>  
<script type="text/javascript" src="jquery.cityselect.js"></script>

$("#city").citySelect();//第一种

$("#city").citySelect({   
    url:"city.min.js",   
    prov:"湖南", //省份  
    city:"长沙", //城市  
    dist:"岳麓区", //区县  
    nodata:"none" //当子集无数据时，隐藏select  
}); //第二种

<div id="city">  
    <select class="prov"></select>   
    <select class="city" disabled="disabled"></select>  
    <select class="dist" disabled="disabled"></select>  
</div>